The present invention relates to a tool ratchet (ratchet) for tightening and loosening screws and/or nuts and the like.
Tool ratchets are commonly known tools, for manually tightening and loosening screws or nuts in particular. A receiving piece is provided for receiving screws, nuts, or adapters (e.g., socket), which is adapted to the contour of the nut, screw, or the adapter, thereby enabling torque to be transferred. The receiving piece is connected with the handle via a ratchet mechanism—also referred to as a freewheel or locking pawl mechanism—such that, in one direction of rotation, torque may be transferred to the screw or nut, while, in the opposite direction, the handle is free to rotate relative to the receiving piece. Tool ratchets typically include a switchover mechanism, with which the direction of torque transfer and the freewheeling direction may be switched.
In addition to the generally known, manually operated tool ratchets, tool ratchets with an integrated electric motor are also known. A tool ratchet of this type is described, e.g., in U.S. Pat. No. 5,562,015. The disadvantage of the known ratchet is that it must be operated with an electric motor. If the handle were rotated in the freewheeling direction with the motor turned off, a nut to be tightened would be loosened, since a load moment would always be present at the receiving piece, due to the permanent mechanical connection with the electric motor.
Publication GB 2354193 A makes known a ratchet-like tool with an electric motor, which does not include a ratchet mechanism, however, and must therefore also be operated with an electric motor.
Publication U.S. Pat. No. 5,924,340 A describes a ratchet tool with a permanently coupled hydraulic linear drive.